The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A power source such as an electrical utility may supply alternating current (AC) power to a refrigerant compressor. The refrigerant compressor includes an electric motor that drives the refrigerant compressor. A system including the refrigerant compressor may also include one or more devices that prevent current flow to the electric motor from exceeding a predetermined value.
For example, a line break protector may be implemented such that current flows through the line break protector before flowing to the electric motor. The line break protector may include an electric heater that generates heat as current flows through the line break protector. The line break protector trips and disables current flow to the electric motor when the current flowing through the line break protector is greater than the predetermined value.
For another example, a positive temperature coefficient (PTC) device and/or a negative temperature coefficient (NTC) device may be implemented in thermal contact with a motor winding to achieve a temperature relative to the temperature of the motor. Resistances of the PTC and/or NTC devices may then be used to determine motor temperature, both directly and indirectly. One or more remedial actions, such as shutting off the motor, can be taken if the motor temperature measured or determined using the PTC and/or NTC devices is greater than a predetermined temperature.